/*
 * Sideband.actor.cpp
 *
 * This source file is part of the FoundationDB open source project
 *
 * Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "fdbclient/NativeAPI.h"
#include "fdbserver/TesterInterface.h"
#include "fdbserver/workloads/workloads.h"
#include "flow/actorcompiler.h"  // This must be the last #include.

struct SidebandMessage {
	uint64_t key;
	Version commitVersion;

	SidebandMessage() {}
	SidebandMessage(uint64_t key, Version commitVersion) : key( key ), commitVersion( commitVersion ) {}

	template <class Ar>
	void serialize( Ar& ar ) {
		ar & key & commitVersion;
	}
};

struct SidebandInterface {
	RequestStream<SidebandMessage> updates;

	UID id() const { return updates.getEndpoint().token; }

	template <class Ar>
	void serialize( Ar& ar ) {
		ar & updates;
	}
};

struct SidebandWorkload : TestWorkload {
	double testDuration, operationsPerSecond;
	SidebandInterface interf;

	vector<Future<Void>> clients;
	PerfIntCounter messages, consistencyErrors, keysUnexpectedlyPresent;

	SidebandWorkload(WorkloadContext const& wcx)
		: TestWorkload(wcx),
		messages("Messages"), consistencyErrors("Causal Consistency Errors"),
		keysUnexpectedlyPresent("KeysUnexpectedlyPresent")
	{
		testDuration = getOption( options, LiteralStringRef("testDuration"), 10.0 );
		operationsPerSecond = getOption( options, LiteralStringRef("operationsPerSecond"), 50.0 );
	}

	virtual std::string description() { return "SidebandWorkload"; }
	virtual Future<Void> setup( Database const& cx ) { 
		return persistInterface( this, cx->clone() );
	}
	virtual Future<Void> start( Database const& cx ) {
		clients.push_back( mutator( this, cx->clone() ) );
		clients.push_back( checker( this, cx->clone() ) );
		return delay(testDuration);
	}
	virtual Future<bool> check( Database const& cx ) {
		int errors = 0;
		for(int c=0; c<clients.size(); c++)
			errors += clients[c].isError();
		if( errors )
			TraceEvent(SevError, "TestFailure").detail("Reason", "There were client errors.");
		clients.clear();
		if( consistencyErrors.getValue() )
			TraceEvent(SevError, "TestFailure").detail("Reason", "There were causal consistency errors.");
		return !errors && !consistencyErrors.getValue();
	}

	virtual void getMetrics( vector<PerfMetric>& m ) {
		m.push_back( messages.getMetric() );
		m.push_back( consistencyErrors.getMetric() );
		m.push_back( keysUnexpectedlyPresent.getMetric() );
	}

	ACTOR Future<Void> persistInterface( SidebandWorkload *self, Database cx ) {
		state Transaction tr(cx);
		BinaryWriter wr(IncludeVersion()); wr << self->interf;
		state Standalone<StringRef> serializedInterface = wr.toStringRef();
		loop {
			try {
				Optional<Value> val = wait( tr.get( StringRef( format("Sideband/Client/%d", self->clientId) ) ) );
				if( val.present() ) {
					if( val.get() != serializedInterface )
						throw operation_failed();
					break;
				}
				tr.set( format("Sideband/Client/%d", self->clientId), serializedInterface );
				wait( tr.commit() );
				break;
			} catch( Error& e ) {
				wait( tr.onError(e) );
			}
		}
		TraceEvent("SidebandPersisted", self->interf.id()).detail("ClientIdx", self->clientId);
		return Void();
	}

	ACTOR Future<SidebandInterface> fetchSideband( SidebandWorkload *self, Database cx ) {
		state Transaction tr(cx);
		loop {
			try {
				Optional<Value> val = wait( tr.get( StringRef( format("Sideband/Client/%d", (self->clientId + 1) % self->clientCount) ) ) );
				if( !val.present() ) {
					throw operation_failed();
				}
				SidebandInterface sideband;
				BinaryReader br(val.get(), IncludeVersion()); br >> sideband;
				TraceEvent("SidebandFetched", sideband.id()).detail("ClientIdx", self->clientId);
				return sideband;
			} catch( Error& e ) {
				wait( tr.onError(e) );
			}
		}
	}

	ACTOR Future<Void> mutator( SidebandWorkload *self, Database cx ) {
		state SidebandInterface checker = wait( self->fetchSideband( self, cx->clone() ) );
		state double lastTime = now();

		loop {
			wait( poisson( &lastTime, 1.0 / self->operationsPerSecond ) );
			state Transaction tr(cx);
			state uint64_t key = g_random->randomUniqueID().hash();
			state Version commitVersion = wait( tr.getReadVersion() );  // Used if the key is already present
			state Standalone<StringRef> messageKey = format( "Sideband/Message/%llx", key );
			loop {
				try {
					Optional<Value> val = wait( tr.get( messageKey ) );
					if( val.present() ) {
						++self->keysUnexpectedlyPresent;
						break;
					}
					tr.set( messageKey, LiteralStringRef("deadbeef") );
					wait( tr.commit() );
					commitVersion = tr.getCommittedVersion();
					break;
				}
				catch( Error& e ) {
					wait( tr.onError( e ) );
				}
			}
			++self->messages;
			checker.updates.send( SidebandMessage( key, commitVersion ) );
		}
	}

	ACTOR Future<Void> checker( SidebandWorkload *self, Database cx ) {
		loop {
			state SidebandMessage message = waitNext( self->interf.updates.getFuture() );
			state Standalone<StringRef> messageKey = format( "Sideband/Message/%llx", message.key );
			state Transaction tr(cx);
			loop {
				try {
					Optional<Value> val = wait( tr.get( messageKey ) );
					if( !val.present() ) {
						TraceEvent( SevError, "CausalConsistencyError", self->interf.id() )
							.detail("MessageKey", messageKey.toString().c_str())
							.detail("RemoteCommitVersion", message.commitVersion)
							.detail("LocalReadVersion", tr.getReadVersion().get()); // will assert that ReadVersion is set
						++self->consistencyErrors;
					}
					break;
				} catch( Error& e ) {
					wait( tr.onError(e) );
				}
			}
		}
	}
};

WorkloadFactory<SidebandWorkload> SidebandWorkloadFactory("Sideband");
